I too have struggled with painfully cold fingers and feet while I code. My hypothesis of what is happening is that when you're resting your arms on the table, you are preventing the free flow of blood in your forearms to your hands. Without warm blood reaching your hands, they get very cold. The same thing applies to your feet as the seat you're sitting in constrains blood flow in your legs.
A good short term solution is to fill a paper cup with hot water and wrap your hands around that. This provides temporary relief but only treats the symptom. The effect wears off quickly.
I have also tried fingerless gloves, but those are completely worthless.
The only real solution is to do some light exercise. Most days after I eat lunch, I will walk around for 30 minutes. This light exercise creates heat in my muscles and thereby heats up my blood. The warm blood can also freely circulate to my hands and feet as nothing is constraining the flow of blood. After about 15 minutes of walking I can feel an internal warmth returning to my hands. The skin is still cold but I know soon enough my hands will be warm again. And the effect lasts the rest of the day.
A good short term solution is to fill a paper cup with hot water and wrap your hands around that. This provides temporary relief but only treats the symptom. The effect wears off quickly.
I have also tried fingerless gloves, but those are completely worthless.
The only real solution is to do some light exercise. Most days after I eat lunch, I will walk around for 30 minutes. This light exercise creates heat in my muscles and thereby heats up my blood. The warm blood can also freely circulate to my hands and feet as nothing is constraining the flow of blood. After about 15 minutes of walking I can feel an internal warmth returning to my hands. The skin is still cold but I know soon enough my hands will be warm again. And the effect lasts the rest of the day.